An app for managing mental health used by the NHS has landed millions of pounds in fresh funding from Neil Woodford-backed Touchstone Innovations and Draper Esprit.

Digital health startup Ieso makes cognitive behavioural therapy available via a smartphone, making it more widely available than face-to-face therapy which is used to create conditions such as anxiety, depression and panic disorders.

The £18m in fresh cash will help the Cambridge-based firm grow in the UK and expand in the US market..

“This financing is a great vote of confidence in Ieso’s ability to become a global leader in mental health delivery and our technology which lies at the intersection of online evidence-based CBT, dynamic artificial intelligence learning, real time therapist support and mobile accessibility, ultimately creating high quality, accessible CBT therapy," said chief executive Dan Clark.

"Up to 60 per cent of people in the US alone have unmet behavioural health needs. This presents a major opportunity for Ieso to make a radical impact on healthcare outcomes and costs."

The value of the backing could still increase, with the round remaining open to previous investors. Touchstone, formerly known as Imperial Innovations and with with Woodford Investment Management one of ts biggest shareholders, first invested in Ieso in 2013 while Draper is a new investor.

Nearly 17,000 patients have been treated in 100,000 hours of therapy with the app and evidence that it can reduce treatment time by 50 per cent.